// PR c++/87523 // { dg-do compile { target c++14 } } template struct my_integer_constant { constexpr my_integer_constant() {} constexpr operator T() const { return v; } constexpr T operator()() const { return v; } }; template struct constant_call { template static void call(T v, Callback f) { char dummy[sizeof...(u)] = { ( (v == u) ? (f(my_integer_constant{}), static_cast(0)) : static_cast(0))... }; (void)dummy; } }; void f(bool reverse_in, bool other_bool_in) { auto helper = [&] (auto reverse_t) { bool constexpr reverse_v = reverse_t; (void)reverse_v; constant_call::call(other_bool_in, [&] (auto newb) { bool reverse_v_dyn = reverse_v; }); }; constant_call::call(reverse_in, [&] (auto reverse_t) { helper(reverse_t); }); }